Earth tamper

ABSTRACT

Earth tamper with a main frame having spaced, reinforced cross members with two trunnions extending normal to the cross members and parallel to a central tongue. A perimeter subframe carrying two tamper wheels is pivotally mounted on each trunnion permitting subframe oscillations when compacting uneven grades. The subframes shift axially between the cross members and along the trunnions when travel direction is reversed placing in engagement alternate sets of force transfer members on main and subframe minimizing bending moments upon tamper wheel axles. Four, independently rotatable tamper wheels of spaced, open ring, spoked construction with sheepsfoot elements projecting outwardly from the ring facilitate short radius turning of the unit without disturbing compacted material. Nonengaging cleaner bars are set on the subframe between adjacent wheel rings. A second form of earth tamper includes only one perimeter subframe mounted upon a trunnion with main frame. Two, independently rotatable tamper wheels with cleaners are mounted on the subframe.

United States Patent Fred Joseph Caron [72] Inventor PrimaryExaminer.lacob L Nackenoff Citr s H ig t- C Attorney-Flehr. Hohbach,Test, Albritton & Herbert [21] Appl. No. 844,465 [22 Filed July 24, 1969[4S] Patented Feb. 2, 1971 ABSTRACT: Eanh tamper with a main framehaving spaced, 73 A i Caron Compactor C reinforced cro'ss members withtwo trunnions extending nor- West Sacramento, Calif. mal to the crossmembers and parallel to a central tongue. A acorporation f C lif niperimeter subframe carrying two tamper wheels is pivotally mounted oneach trunnion permitting subframe oscillations when compacting unevengrades. The subframes shift axially between the cross members and alongthe trunnions when travel direction is reversed placing in engagementalternate I 54] EARTH TAMPER sets of force transfer members on main andsubframe minimiz- 10 Claims 8 Drawing Figs. ing bending moments upontamper wheel axles. Four, independently rotatable tamper wheels ofspaced, open ring, Cl 94/50 spoked construction with sheepsfoot elementsprojecting outl l Cl E016 19/24 wardly from the ring facilitate shortradius turning of the unit of Search without disturbing compactedmaterial Nonengaging cleaner bars are set on the subframe betweenadjacent wheel rings. [56] References A second form of earth tamperincludes only one perimeter UNlTED STATES PATENTS subframe mounted upona trunnion with main frame. Two, in- 2,437,524 3/ 1948 Harrison 94/50dependently rotatable tamper wheels with cleaners are 2,587,463 2/ l952Guignard 94/50 mounted on the subframe.

28 s 3| 58 l3 9 27 I6 Uh [1 lEq l7 I I U \L I l U L6 v SHEET 2 BF 4 n 1I I!!! 1/ FI IG 5 INVENTOR. FRED JOSEPH. CARON ATTORNEYS v PATENTEU FEB?1911- SHEET 0F 4 FlG '8 INVENTOR. FRED JOSEPH CARON FIGJ BY 7 IATTORNEYS EARTH TAMPER BACKGROUND OF THE INVENTION This inventionconcerns improvements to earth tampers and particularly earth tam'persof the sheepsfoot type.

Sheepsfoot rollers, in general, were designed and adapted to bepropelled by track laying tractors. This combination is characterized inoperation by moderate to low compaction speeds and avoidance of shortradius turns where the sheepsfoot could p|ow out compacted materialalready in place.

The advent of the rubber-tired tractor characterized by relatively highworking speeds and short radius turning created the need for acompatible sheepsfoot tamper which would work at a higher speed andwhich would be turned in a short radius without destructive effect tothe compacted material in place.

The predominant design of the prior art earth tampers or sheepsfootrollers comprised a large hollow steel drum serving as both a ballastcompartment for wet sand or water, andas a support for the outwardlyprojecting sheepsfoot shanks and caps. The drum in certain arrangementshad its own subframe mounted, in turn, to a main or principal frame.Cleaner mechanisms were placed close to the drum surface between thesheepsfoot element to remove clay and other materials which tended tobridge over. This raker bar construction frequently imposed a brakingeffect due to the rakers being operated in close drag-contact with thesolid drum.

For transport of earth tampers of this variety from one job site toanother, different schemes were employed. Certain of the earth tampersof narrow dimensions were transported without disassembly on machinerycarriers and the limitation of highway load widths determined themaximum size of the tamper. Other earth tampers were partiallydisassembled for transport and reassembled at the new job site.Sheepsfoot of this construction were of larger overall width than theformer and disassembly was usually achieved by disassembly of theprincipal framework.

Where the drum type sheepsfoot roller was employed, transport of theunit required that the ballast be drained from the drum and left at thefirst job site.

SUMMARY OF THE INVENTION AND OBJECTS The invention, in summary,comprises a main frame for an earth tamper including a longitudinallyextending, central tongue member with crossmembers'rigidly securedthereto extending laterally from each side thereof. Two wheel-frameguide members or trunnions are arranged parallel to the central beammember, each guide member extending between and rigidly secured to thespaced crossmembers, Two wheelframe assemblies are provided, one mountedon each wheelframe guide member and each assembly includes a generallyrectangular perimeter frame mounting two independently rotatable earthtamping wheels with wheel cleaner extending between the subframe andwheels. The wheel frame assembly is free to pivot about the wheel guidemember when traversing uneven ground and the wheel-frame assembly isshiftable longitudinally along the axis of the guide member duringchange of direction of travel. Complementary mounted pusher and reactionmembers are arranged on the main frame and wheel frame, respectively, totransfer motive forces from the main frame to the wheel-frame assembly.

An object of this invention is to provide an improved earth tamper whichis readily disassembled for transport from one job site to another.

Another object of the invention is to provide an earth tamper of thesheepsfoot type having a plurality of independently rotatable, open-ringwheels upon which are mounted sheepsfoot tamping elements, the wheelsbeing mounted in groups of two upon a subframefree to oscillate or pivotabout an axis parallel to the direction of travel.

Another object of the invention is to provide an earth tamper of thetype described wherein the motive forces are applied through a centraltongue member and are distributed therefrom to wheel mounting subframesin a manner which minimizes bending moments at the wheel axles.

Another object of the invention is to provide an improved earth tampingwheel of the sheepsfoot type including a wheel cleaner arrangementpermitting deep penetration of the tamping elements while minimizingbraking and drag effects between the cleaner mechanisms and the wheelsbeing cleaned.

A further object of the invention is to provide an improved earth tamperhaving a double-oscillation suspension of multiple, free wheeling,compaction wheels, which tamper unit may be turned within its own widthwithout increased draft, plowing, or disturbing compacted materialalready in place and which is complementary in operating characteristicsto quick turning, rubber-tired tractors.

Further objects and features of the invention will appear from thedrawings taken in conjunction with the specification.

BRIEF DESCRIPTION OF DRAWINGS FIG. I is a plan view of an earth tamperof the present invention.

FIG. 2 is an elevation view, partially broken away, of the earth tampershown in FIG. I.

FIG. 3 is an enlarged, fragmentary sectional view along the line 3-3 inFIG. 1.

FIGS. 4 and 5 are each sectional views like FIG. 3 but takenrespectively along the lines 44 and 5-5 of FIG. 1.

FIG. 6 is an enlarged transverse view, partially fragmentary, along thelines 6-6 of FIG. 1 showing one set of two tamper wheels operating on ahorizontal grade while the other set operates on an inclined grade.

FIG. 7 is a plan view of a second form of an earth tamper of the presentinvention.

FIG. 8 is an elevation view of the earth tamper shown in FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An earth temper 10 of thepresent invention is shown generally in FIGS. 1 and 2 and comprises amain frame 11 upon which are mounted two, substantially identicalwheelframe assemblies I2 and 13.

The main frame 11, FIGS. I-6, includes a longitudinally extendingcentral beam or tongue member 14 which is provided at the forward endwith a hitch 16 for connection to a tractor (not shown) for moving thetamper I0 across the fill. The opposite end of the tongue or beam 14 isprovided with a pusher plate 17 which serves to protect the end of thebeam from aggressive thrust imparted by vehicles pushing against theplate 17. The central beam or tongue member 14 extends the full lengthof the main frame and is the principal load carrying member on' theearth tamper I0. The central beam 14 may be fabricated by joiningtogether, toe-to-toe, a pair of l2- inch, 45-pound structural channelmembers 18, FIG. 3, which at the forward end'may be supplemented by afurther pair of 12 inch channels 19 set back-to-back to the channels I8.Being of substantial section, the tongue or beam member I4 is capable ofwithstanding substantial forces which may be imparted to it during earthworking operations of the tamper without noticeable deformation.

Box-sections, crossmembers 2I24 are rigidly secured, as by welding, tothe sides of the tongue member and project outwardly therefrom in atransversely aligned, longitudinally spaced apart relationship. A bracemember 26 is rigidly secured between an outer end of each crossmemberand the tongue member 14, as in FIG. 1. Acting together, the bracemember 26, central beam I4, and the associated crossmember serve as ahorizontal platform to support a ballast element 27, preferably in theform of a wedge-shaped concrete block 27 equipped with a lifting hook 28Ballast 27 may be supplied to the earth tamper 10 in various amountsdepending upon the specifications and requirements of the work beingperformed. The ballast maintains its position on the main frame solelyfrom the action ofgravity and friction between the ballast and framemembers. This arrangement of ballast is distinct from the employed inprior sheepsfoot tampers wherein the hollow drum was usually filled withwater or wet sand to obtain the desired weight for compaction.

A wheel-frame guide member or trunnion 29 extends between theerossmembers 21-23. and between the crossmcmbers 22-24. The trunnion isrigidly secured to the crossmembers as shown in FIGS. 4 and 5. The guidemember 29 or trunnion is cylindrical in cross section and may befabricated from structural tubing sized in accordance with its functionof supporting and guiding the wheel-frame assembly described below.

Being that the wheel-frame assemblies 12 and 13 are virtually identical,the description below will apply to both. Each wheel-frame assemblyincludes a generally rectangular perimeter frame 31, FIGS. 1, 2 and 6,within which are mounted two tamper wheels of open ring, spokedconfiguration, comprising an outboard wheel 32 and an inboard wheel 33.As shown, the wheel 32 includes three spaced rings and the wheel 33,four rings, although the number of rings may be varied depending on thewidth of the machine required.

The perimeter frame 31 may be fabricated from structural box members andincludes three longitudinally extending members 34 (FIG. 6), two beingarranged on the sides and one being somewhat centrally disposed in theregion of connection with the trunnion 29, FIGS. 1 and 6. The endmembers 36 are rigidly secured to the long members 34. Pillow blocks 37are mounted in midspan of the long members 34, for receiving the ends ofan axle 38 of the tamper wheel. Thus, a pair of pillow blocks 37 on thelong members 34 support a tamper wheel which rotates independently ofthe other tamper wheels.

The arrangement of the wheel-frame assembly and the main frame 11 issuch as to permit eaeh wheel frame assembly to shift longitudinallyalong the guide members 30 when the tamper changes direction. Further,each wheel-frame assembly may pivot about the axis of the guide members,FIG. 6, to permit more effective tamping or earth treatment on berms andinclines. To this end, the perimeter frame 31 has a length somewhatshorter than the distance between the cross arms 21-23 and 22-24, 24, asshown in FIG. 1 of the main frame. The perimeter frame 31 is united forrapid disassembly to the main frame by the connector 41.

The connector or split coupling 41, FIGS. 4 and 5, is mounted to eachwheel-frame end member 36 by two plates 42, 43 arranged respectively onthe outside and inside of the end member 36, and placing the axis of theconnector 41 a distance below the end member 36. It will be alsoappreciated here that the axis or the connector 42 and guide member 29is arranged below the axis of the tamper wheels which are mounted inpillow blocks arranged on the member 34, as is evident from FIG. 6.Thus, the wheel-frame assembly pivots about an axis arranged below theaxis of rotation of the tamper wheels.

The connector or split coupling 41 cooperates with the wheel-frame guidemember 29 to permit the wheel-frame assembly to pivot about the axis ofthe guide member and to slide axially therealong. To facilitate thesefunctions, the internal surface of the split coupling is provided withsuitable bearing materials well known in the art. The connector or splitcoupling provides for ready disassembly of wheel-frame assembly from themain frame. To this end a lower or removable portion 44 of the couplingis dismountableby unsecuring the fasteners or bolts 43. Then thesubframe assembly, including tamper wheels, may be vertically liftedfrom the main frame for transporting the earth tamper over the highwayin a compact condition.

Referring to 'FIGS. 3-5, to transfer motive forces from the central beamor tongue 14 to the wheel-frame assemblies, each crossmember 21-24 isequipped, adjacent its ends, with two pusher members 46-47. The pushermember 46 is arranged adjacent to the guide member and the pusher member47 is disposed inwardly adjacent to the central beam member 14. Thepusher members 46,47 are rigidly secured to the crossmembers on the sidethereof facing the perimeter wheelframe and extend upwardly forengagement therewith. A gusset 48 rigidly secured to the crossmcmber andpusher member reinforces each pusher member longitudinally of the mainframe.

Complementary arranged reaction members are included on the perimeterframe of the wheel-frame assembly. The outer plate 42 of the connector41 serves as one reaction member, and laterally inwardly thereofa plate50, FIG. 6, is positioned for engagement with the pusher member 47 toserve as a second reaction member.

When the earth tamper I0 is towed or pushed to the left as viewed inFIGS. 1 and 2, there is a space 49 between the reaction and pushermembers adjacent to the forward portion of the tamper, FIG. 4. Thereaction and pusher members to the rear of the tamper arc in contact asshown in FIG. 5. Thus, the motive forces are carried from the tonguemember 14 to the crossmembers 23, 24 and the pusher members 46, 47 ofthe main frame to the wheel-frame subassemblies, the reaction members ofwhich engage the pusher members 46, 47. When the earth tamper 10 ismoved in the opposite direction, the wheel-frame assembly shiftslongitudinally along the guide member 29 so that the conditionsillustrated in FIGS. 4 and 5 are reversed. An important advantage ofthis arrangement is that the towing forces are taken by the main andsubframes without applying *bending stresses to the wheel axles.

The wheel-frame assembly may also oscillate aboutthe axis of the guidemember, FIG. 6, so that one or both wheel assemblies may be inclinedwith respect to the main frame; Stop means 51 are provided between thecentral beam member 14 and the wheel-frame assembly, FIGS. 1 and 6, andincludes a reinforced cutout in the central beam 14 supplied withinclined plates 52 which are positioned to be engaged by the inboardpillow blocks 37 when the frame assembly is tilted upwardly as shown inFIG. 6. When the frame assemblies are tilted oppositely, e.g., theinboard members 34 being elevated over the outboard members 34, theinboard long side members 34 of the wheel-frame assemblies engaged andthus limit upward movement or tilting action of the subassemblies andprotects the inboard wheel from engagement with the central beam 14.

As may be seen from FIG. 1, the outboard tamper wheels 32 are mountedfor rotation substantially entirely outwardly of the main frame and theinboard wheels 31 rotated in a zone disposed entirely inwardly of thecompass of the main frame. Each wheel is independently joumaled to theperimeter frame assembly and thus is free wheeling so as to permit theearth tamper 10 to be turned within its own radius without increaseddraft, plowing, or disturbing compacted material already in place. Thisfeature makes the earth tamper 10 particularly adaptable to darn workand areas where a limited working space is available. The earth tamperis also compatible with the high speeds and quick turningcharacteristics of rubberwheeled tractors.

Each tamper wheel includes an axle 56 mounted with its opposite ends inone of the pillow blocks 37 and the axle is rigidly secured to.acylindrical hub member 57. A plurality of axially spaced apart rings 58are rigidly secured to the hub 57 by an array of radially extendingspokes 59 which preferably are of cylindrical cross section and of adiameter substantially identical to the ring width to avoid bridging andcollection of material between adjacent spokes.

Earth tamping feet 61 including a shank 62 and cap-63 are secured uponand project outwardly from the peripheral surface of each of the rings58 in evenly spaced relation. The tamping feet 61 on adjacent rings maybe staggered relative to each other.

Raker bars 66 are fixedly secured to the end members 36 of the perimeterframe and extend through the gaps between adjacent rings on the wheelsto prevent rocks, clay and other unwanted material from lodging therepermanently. The openring sheepsfoot wheel and raker bar arrangementdescribed allows deep penetration through soft material from the tip ofthe cap to the surface of the hub, without excessive rolling resistanceor the possible bridging-over effect in the fill which is a commoncharacteristic of solid-drum sheepsfoot compactors.

OPERATION When considering the operation of the earth tamper 10, itshould first be assumed that the tamper is delivered to the job site inknocked-down condition for the reason that in the assembled conditionthe earth tamper is too large to be moved over the highways as a legalload. The main frame 11 may be unloaded from the machinery carrier andsetupon blocking at a suitable height so as to receive each of the twowheel-frame assemblies 12, 13. The split coupling, or connector41, ateach end of the wheel-frame assembly 12 or 13, is disassembled, if thatoperation has not been previously performed, by removing the lowerportion 44. Each wheel-frame assembly is placed with the use of a craneor the like so that the connectors 41 engage the upper portions of thetrunnions or guide members 29. Thereafter the lower portion of thecoupling 44 is secured in place with the two fasteners and the tamper 10is then ready to be connected to a tractor for work. It will beunderstood that the wheel-frame assemblies during transport from onesite to another have mounted thereon the inner and outer tamper wheels32, 33, and that it is unnecessary to dismount the wheels from thesubframe assemblies for transport purposes. Thus, to assemble ordisassemble the earth tamperlO it is necessary only to deal with eightfasteners of the four couplings or connectors 41. l

The ballast blocks 27, when such are needed, may be mounted upon theballast platforms to achieve the compaction required by the jobspecification.

When the compactor is towed from rest, the pusher members 46, 47 on themain frame move forward into engagement with the reaction members 48 onthe wheel frame, thus transferring the propelling forces from the mainframe to the two subframes. Between the forward sets of complementarypositioned reaction and pusher members there is at this time a space 49between the main frame and wheel-frames so as to insure clearance,preventing bindingof the members which would prevent the wheel-framesfrom oscillating freely on the trunnions.

When the tamper 10 is turned in a short radius in a clockwise directionas viewed in FIG. 1, the forward pusher and reaction members pertainingto the wheel frame assembly 12 come into engagement while the rearwardlydisposed reaction and pusher members pertaining to the wheel-frameassembly 13 are engaged. The wheels on the right-hand wheelframeassembly are each free to move in the direction reverse to the wheels inthe left-hand frame, left-hand wheel-frame assembly 13. Permitting thewheels of one frame to turn independently of those of another providesthe feature that the tamper 10 may be turned in a short radius withoutthe inner wheels in the turn plowing out the previously compactedmaterial. When the earth tamper 10 is employed upon a berm or bank suchas indicated in FIG. 6, one wheel-frame with a set of compaction wheelsmay pivot on the wheel guides permitting the wheels to operateconforrnably on the bank, while the other compaction wheels operate onthe flat portion. Similar oscillations of the wheels-frames on the wheelguides or trunnions occur as uneven grades are traversed.

SECOND EMBODIMENT of employing five axially spaced rings 58 supportingthe tamping feet 61, previously described.

The main frame 71 includes a forward tongue member 76 fixed secured tothe transversely extending cross members 77, 78 and braced with respectthereto by the struts 79. The forward portion of the tongue members 76is equipped with a hitch assembly 81. Being generally rectangular inoutline. the main frame includes'side frame members 82, 83 and rearcrossmembers 84. A wheel-frame guide member or trunnion 86 extends fromthe rear cross member 84 to the tongue member 76.

The wheel-frame assembly 72 is constructed and arranged substantiallysimilar to the wheel-frame assembly 13, prcviously described, with theexception of the location of the split coupling connector members 85which are disposed in midspan of the end members 87 of the subframe. Theother details of the connector 85 are identical to that shown in FIGS. 4and 5. Pusher members 91 are arranged on the main frame crossmembers inconfronting relationship to the reaction members 92 disposed on the endmembers of the peripheral frame of the wheel-frame assembly and functionsimilar to the relationship described previously in relation to FIGS. 4and 5. Raker or cleaner bars 66 are also provided on the subframeextending through the gaps between adjacent rings 58.

The earth tamper 70 is particularly satisfactory on smaller operationsand may be equipped with ballast blocks 93 similar to those describedabove. The wheel subframe assembly oscillates about the guide member ortrunnion 86 and the two tamping wheels 72 are each free wheeling,permitting the tamper 70 to be turned in a very small space withoutdigging up the ground previously compacted.

It will be seen from the foregoing that there has been disclosed animproved earth tamping machine which may be readily disassembled so asto permit the wheel-frame subassemblies to be removed from the mainframe and placed on a road carrier. The present tamper is of anarrangement giving a wide working track yet being transportable withoutexceeding the highway width limits requiring special permits for roadtravel. The subject earth tamper is simple and rugged in design andincorporates free wheeling characteristics for the tamper wheels so thatthe unit may be turned around in a small area without digging up thepreviously compacted fill.

While the above description has been set forth in compliance with thePatent Statutes and Rules, the invention is not limited except asdefined in the following claims.

Iclaim:

1. An earth tamper comprising a main frame structure including alongitudinally extending, central tongue member, hitch means on one endof said tongue member serving to connect said earth tamper to a tractorvehicle, crossmembers rigidly secured to said tongue member extendinglaterally from each side of the centerline thereof at two longitudinallyspaced locations, at least one wheel-frame guide member arrangedparallel to said tongue member extending between and rigidly secured tosaid spaced crossmembers, and a wheelframe assembly mounted on eachwheel-frame guide member, said assembly including a generallyrectangular, perimeter wheel-frame, two compaction wheels each mountedon said wheel-frame for independent rotation, said main frame andwheel-frame assembly being dimensioned to permit limited longitudinalmovement of said assembly between said spaced crossmembers, meansconnecting said wheel-frame guide member of said main frame and saidwheel-frame assembly in a connection permitting said assembly to pivotabout the axis of said guide member and to shift longitudinally thereofduring change of direction of said earth tamper, and complimentarymounted pusher and reaction means on said main frame and saidwheel-frame, respectively, to transfer motive forces from said mainframe to said wheel-frame assembly.

2. The earth tamper defined in claim 1 wherein said pusher and reactionmeans are arranged in forward and rear sets at each end of saidwheel-frame assembly, the forward set of said pusher and reaction meansbeing in nonengagement during forward motion of said tamper, and therear set being in nonengagement during rearward motion of said tamper.

3. The earth tamper defined in claim I wherein said connector means isreadily disengageablc permitting ready dismounting of said wheel frameassembly from said main frame permitting shipping of said tamper overthe road to another work site.

4. The earth tamper defined in claim 1 and further including at least atthe forward portion of said tamper, members extending between saidtongue and said crossmembcrs serving to define a ballast platform andballast in solid form disposed on said platform.

5. The earth tamper defined in claim I wherein said wheel frame guidemember is aligned with the centerline of said ton gue and member.

'6. The earth compactor defined in claim 1 wherein said main frameincludes two wheel-frame guide members laterally spaced from thecenterline of said tongue member and disposed parallel thereto, and twosaid wheel-frame assemblies mounted upon the respective guide members.

7. An earth tamper comprising a main frame structure including alongitudinally extending, central tongue member, hitch means at one endof said tongue member to connect said tamper with a tractor vehicle,pusher plate means on the other end of said tongue member to receivethrust from a pusher vehicle, crossmembers rigidly secured to saidtongue member extending laterally therefrom on each side of the tonguecenterline at two longitudinally spaced locations intermediate the endsof said tongue member, two wheel-frame guide members each arrangedparallel to said tongue member and spaced laterally outwardly therefrom,one on each side of the tongue centerline, each guide member extendingbetween two spaced crossmembers and being rigidly secured thereto, andtwo wheel-frame assemblies, one arranged on each side of the tonguecenterline and disposed upon one of the wheel-frame guide members, eachwheel-frame assembly including a generally rectangular, perimeterwheel-frame disposed above one of said wheel-frame guide members,connector means between said wheel-frame and its associated guide memberextending downwardly from the end portions of said wheelframe, saidconnector means being pivotable with respect to said guide member,permitting said wheel-frame assembly to oscillate about the axis of saidguide member, two compaction wheels of the sheepsfoot type mounted oneach wheel-frame, each wheel being independently rotatable with respectto the other wheel about an axis arranged above the axis of said guidemember, compaction wheel cleaner means mounted on said wheel-frame inoperative relative to said compaction wheels, said main frame and saidwheel-frame assemblies being dimensioned to permit longitudinal movementof said wheel-frame assemblies in the spaced between said crossmembers,and complementary arranged pusher and reaction means on the crossmembersof said main frame and the end members of said wheel-frames,respectively, serving to transfer motive forces from said main frame tosaid wheel-frame assemblies.

8. The earth tamper defined in claim 7 wherein each compaction wheelincludes a cylindrical, axially extending hub, an axle including meansfor mounting said wheel to said wheelframe, means serving to mount saidhub to said axle, a plurality of axially spaced apart rings having adiameter substantially greater than that of said hub, a plurality ofcylindrical spokes rigidly mounting said rings to said hub, said ringshaving an axial width substantially equal to the width of said spokes,sheepsfoot compaction means arranged on said rings projecting radiallyoutwardly therefrom, said wheel being constructed and arranged so thatdull penetration for compaction is substantially unobstructed by wheelstructure between laterally adjacent rings from the ends of saidsheepsfoot compaction means to the outer surface of said hub.

9. Earth tamper defined in claim 7 wherein stop means are provided forlimiting pivoting of said wheel-frame assemblies on said wheel-frameguide members.

10. The earth tamper defined in claim 1 wherein there is providedcompaction wheel cleaner means mounted on said wheel-frame in operativerelation to said compaction wheel.

1. An earth tamper comprising a main frame structure including alongitudiNally extending, central tongue member, hitch means on one endof said tongue member serving to connect said earth tamper to a tractorvehicle, crossmembers rigidly secured to said tongue member extendinglaterally from each side of the centerline thereof at two longitudinallyspaced locations, at least one wheel-frame guide member arrangedparallel to said tongue member extending between and rigidly secured tosaid spaced crossmembers, and a wheel-frame assembly mounted on eachwheel-frame guide member, said assembly including a generallyrectangular, perimeter wheel-frame, two compaction wheels each mountedon said wheel-frame for independent rotation, said main frame andwheel-frame assembly being dimensioned to permit limited longitudinalmovement of said assembly between said spaced crossmembers, meansconnecting said wheel-frame guide member of said main frame and saidwheel-frame assembly in a connection permitting said assembly to pivotabout the axis of said guide member and to shift longitudinally thereofduring change of direction of said earth tamper, and complimentarymounted pusher and reaction means on said main frame and saidwheel-frame, respectively, to transfer motive forces from said mainframe to said wheel-frame assembly.
 2. The earth tamper defined in claim1 wherein said pusher and reaction means are arranged in forward andrear sets at each end of said wheel-frame assembly, the forward set ofsaid pusher and reaction means being in nonengagement during forwardmotion of said tamper, and the rear set being in nonengagement duringrearward motion of said tamper.
 3. The earth tamper defined in claim 1wherein said connector means is readily disengageable permitting readydismounting of said wheel frame assembly from said main frame permittingshipping of said tamper over the road to another work site.
 4. The earthtamper defined in claim 1 and further including at least at the forwardportion of said tamper, members extending between said tongue and saidcrossmembers serving to define a ballast platform and ballast in solidform disposed on said platform.
 5. The earth tamper defined in claim 1wherein said wheel frame guide member is aligned with the centerline ofsaid tongue and member.
 6. The earth compactor defined in claim 1wherein said main frame includes two wheel-frame guide members laterallyspaced from the centerline of said tongue member and disposed parallelthereto, and two said wheel-frame assemblies mounted upon the respectiveguide members.
 7. An earth tamper comprising a main frame structureincluding a longitudinally extending, central tongue member, hitch meansat one end of said tongue member to connect said tamper with a tractorvehicle, pusher plate means on the other end of said tongue member toreceive thrust from a pusher vehicle, crossmembers rigidly secured tosaid tongue member extending laterally therefrom on each side of thetongue centerline at two longitudinally spaced locations intermediatethe ends of said tongue member, two wheel-frame guide members eacharranged parallel to said tongue member and spaced laterally outwardlytherefrom, one on each side of the tongue centerline, each guide memberextending between two spaced crossmembers and being rigidly securedthereto, and two wheel-frame assemblies, one arranged on each side ofthe tongue centerline and disposed upon one of the wheel-frame guidemembers, each wheel-frame assembly including a generally rectangular,perimeter wheel-frame disposed above one of said wheel-frame guidemembers, connector means between said wheel-frame and its associatedguide member extending downwardly from the end portions of saidwheel-frame, said connector means being pivotable with respect to saidguide member, permitting said wheel-frame assembly to oscillate aboutthe axis of said guide member, two compaction wheels of the sheepsfoottype mounted on each wheel-frame, each wheel being independentlyrotatable with respect to the other wheel about an axis arranged abovethe Axis of said guide member, compaction wheel cleaner means mounted onsaid wheel-frame in operative relative to said compaction wheels, saidmain frame and said wheel-frame assemblies being dimensioned to permitlongitudinal movement of said wheel-frame assemblies in the spacedbetween said crossmembers, and complementary arranged pusher andreaction means on the crossmembers of said main frame and the endmembers of said wheel-frames, respectively, serving to transfer motiveforces from said main frame to said wheel-frame assemblies.
 8. The earthtamper defined in claim 7 wherein each compaction wheel includes acylindrical, axially extending hub, an axle including means for mountingsaid wheel to said wheel-frame, means serving to mount said hub to saidaxle, a plurality of axially spaced apart rings having a diametersubstantially greater than that of said hub, a plurality of cylindricalspokes rigidly mounting said rings to said hub, said rings having anaxial width substantially equal to the width of said spokes, sheepsfootcompaction means arranged on said rings projecting radially outwardlytherefrom, said wheel being constructed and arranged so that dullpenetration for compaction is substantially unobstructed by wheelstructure between laterally adjacent rings from the ends of saidsheepsfoot compaction means to the outer surface of said hub.
 9. Earthtamper defined in claim 7 wherein stop means are provided for limitingpivoting of said wheel-frame assemblies on said wheel-frame guidemembers.
 10. The earth tamper defined in claim 1 wherein there isprovided compaction wheel cleaner means mounted on said wheel-frame inoperative relation to said compaction wheel.